yuen: Yuen's test for trimmed means
In WRS: A package of R.R. Wilcox' robust statistics functions

Perform Yuen's test for trimmed means on the data in x and y. The default amount of trimming is 20% Missing values (values stored as NA) are automatically removed.

A confidence interval for the trimmed mean of x minus the the trimmed mean of y is computed and returned in yuen$ci. The p-value is returned in yuen$p.value

For an omnibus test with more than two independent groups, use t1way. This function uses winvar from chapter 2.

1	yuen(x, y, tr = 0.2, alpha = 0.05)

`x`
`y`
`tr`
`alpha`

##---- Should be DIRECTLY executable !! ----
##-- ==>  Define data, use random,
##--	or do  help(data=index)  for the standard data sets.

## The function is currently defined as
function (x, y, tr = 0.2, alpha = 0.05) 
{
    if (tr == 0.5) 
        stop("Using tr=.5 is not allowed; use a method designed for medians")
    if (tr > 0.25) 
        print("Warning: with tr>.25 type I error control might be poor")
    x <- x[!is.na(x)]
    y <- y[!is.na(y)]
    h1 <- length(x) - 2 * floor(tr * length(x))
    h2 <- length(y) - 2 * floor(tr * length(y))
    q1 <- (length(x) - 1) * winvar(x, tr)/(h1 * (h1 - 1))
    q2 <- (length(y) - 1) * winvar(y, tr)/(h2 * (h2 - 1))
    df <- (q1 + q2)^2/((q1^2/(h1 - 1)) + (q2^2/(h2 - 1)))
    crit <- qt(1 - alpha/2, df)
    dif <- mean(x, tr) - mean(y, tr)
    low <- dif - crit * sqrt(q1 + q2)
    up <- dif + crit * sqrt(q1 + q2)
    test <- abs(dif/sqrt(q1 + q2))
    yuen <- 2 * (1 - pt(test, df))
    list(ci = c(low, up), p.value = yuen, dif = dif, se = sqrt(q1 + 
        q2), teststat = test, crit = crit, df = df)
  }